Utility knives generally include a handle and at least one replaceable blade. Because such blades are known to become worn or damaged, utility knife handles generally include provisions to allow a blade to be removed from the handle, so that the blade may be reversed in the handle (in order to provide a new cutting edge for the knife) and/or replaced by another blade.
In the case of many utility knives, the removal of a worn or damaged blade requires that the handle first be opened to gain access to the internal cavity inside the handle. However, because it is sometimes inconvenient to open the handle, some utility knives provide mechanisms that allow a blade to be removed without any need for first opening the handle. Such mechanisms often make use of a releasable catch that engages the replaceable blade within the handle, along with a manually operable mechanism for causing the releasable catch to disengage from the blade. Most of these mechanisms allow a worn or damaged blade to be removed through a blade opening at the front end of the handle.
These and other types of mechanisms require an additional actuator, such as a button and associated hardware mounted in a side wall of the housing, that is depressed in order to cause the releasable catch to disengage from the blade. Thus, such retractable blade utility knives require at least two actuators, one to move the blade and blade carrier between retracted and extended positions, and another to release the blade when located in an extended position. In addition, notwithstanding the availability of such mechanisms, there are still occasions in which a handle must be opened, for example, in order to retrieve a spare blade that may be stored inside the handle or to perform repair or maintenance inside the handle. Unfortunately, upon opening the handle, many of the above-mentioned mechanisms can fall out and become separated from the handle, thereby rendering the mechanism unusable.
As with blades, handles also can become worn or damaged due to demanding operating conditions, such as in the course of regular use in cutting asphalt roof tiles. Consequently, utility knife handles are sometimes formed of metal (e.g., steel) to provide durability. However, even knives with steel handles continue to become worn and/or damaged frequently, on account of such operating conditions.
Accordingly, it is an object of the present invention to overcome one or more of the above-described drawbacks or disadvantages of the prior art.